Weft-passing device for a shuttleless loom

ABSTRACT

A weft-transfer device for a shuttleless loom comprises a needle having at one end a grab with a fixed jaw and a pivotal jaw spring-urged to the closed position, a spring-loaded sliding catch for engaging a tail on the pivotal jaw and holding the latter open, a cam formation on said tail for engaging an abutment to effect engagement of the catch and tail, upon movement of the needle in one direction and near the end of its passage out of the shed, a projection connected to the sliding catch, and a stop which is engaged by said projection to release the catch when the needle moves in the other direction to its position for catching a weft thread.

United States Patent [72] Inventor Bernard Geiger Mulhouse, France [21]Appl. No. 881,1 18

[22] Filed Dec. 1, 1969 [45] Patented [73] Assignee Oct. 19, 1971Societe Alsacienne de Constructions Mecaniques de Mulhouse Mulhouse,France [32] Priority Dec. 3, 1968 [3 3] France [31] 176,354

[54] WEFT-PASSING DEVICE FOR A SHUTTLELESS LOOM 8 Claims, 3 DrawingFigs. 1 [52] US. Cl 139/122 [51] Int.Cl 003d 47/20 [50] Field of Search..l39/122-134 [56] References Cited UNITED STATES PATENTS 2,960,11711/1960 Shimwell 139/122 3,384,126 5/1968 Golobart 139/122 3,386,4776/1968 Durand 139/123 FOREIGN PATENTS 1,391,346 l/l965 France 139/122Primary Examiner-Henry S. Jaudon Attorneyl-lolman & Stern ABSTRACT: Aweft-transfer device for a shuttleless loom comprises a needle having atone end a grab with a fixed jaw and a pivotal jaw spring-urged t0 theclosed position, a springloaded sliding catch for engaging a tail on thepivotal jaw and holding the latter open, a cam formation on said tailfor engaging an abutment to effect engagement of the catch and tail,upon movement of the needle in one direction and near the end of itspassage out of the shed, a projection connected to the sliding catch,and a stop which is engaged by said projection to release the catch whenthe needle moves in the other direction to its position for catching aweft thread.

WEFT-PASSING DEVICE FOR A SHUTTLELESS LOOM This invention relates toweft-transfer devices for shuttleless weaving looms, and especially, butnot exclusively, exit wefttransfer devices designed to take up, in themiddle of the shed, the weft threads passed to them by a feederweft-transfer device.

More particularly, the invention relates to such a device of the typecomprising a needle terminating in a grab having a fixed jaw and amovable jaw urged towards the fixed jaw by elastic return means, meansfor retaining the mobile jaw in the open position, means forneutralizing the said retaining means when the needle reaches a positionfor taking up a weft thread, and means for controlling the opening ofthe movable jaw when the needle is near the end of its passage out ofthe shed.

Known weft-transfer devices of this type have a disadvantage in thatthey comprise a large number of moving parts which react on one anotherso that their functioning is not as precise as is desirable in loomswhich are being made to operate faster and faster in order to complywith the evolution of a technology whose aim is continuously to increaseperformance and production. Moreover, such known devices have a furtherdisadvantage, by virtue of their particular struc-' ture, in that theyseem to have a certain sensitivity to accelerations, whetherlongitudinal or transverse, with the result that, from a certain speedof operation onwards, untimely occurrence of the opening or closing ofthe pincers tends to arise.

An object of the present invention is to provide a wefttransfer deviceof the type aforesaid, in which the above-mentioned drawbacks areobviated or mitigated.

According to the present invention we provide a wefttransfer device fora shuttleless weaving loom comprising a needle terminating in a grabhaving a fixed jaw and a movable jaw urged by resilient return meanstowards the fixed jaw, means for retaining the movable jaw in an opencondition, means for neutralizing the said retaining means when theneedle reaches a position for catching a weft thread, and means forcontrolling the opening of the movable jaw when the needle is near theend of its passage out of the shed, in which the movable jaw ispivotable on the fixed jaw about a transverse axis, and has an extensionbeyond said axis, the means for retaining the movable jaw in the opencondition comprises a slide movable longitudinally in the needle andresiliently urged against said extension of the movable jaw, said meansfor neutralizing said retaining means comprises a projection on a boltwhich is movable longitudinally of the needle and is secured to saidslide, and a stop in the path of said projection, the means forcontrolling the opening of the movable jaw comprises a stationaryabutment located in the path of said extension of the movable jaw.

The device, thus, has only a small number of parts and, apart from itslow cost, it is robust and reliable in operation, the more so in that itis substantially insensitive to accelerations, since the movable jaw ismounted on the fixed jaw, and is balanced by the presence of its saidextension, and, in addition, the slide and its control bolt can be verylight in weight, thus present only a negligible inertia relative to thestrength of their return spring. The locking of the grab in the openposition and the clamping of the thread in the closed position easilyresist forces clearly stronger than those which may arise as a result ofthe strongest acceleration occurring. Moreover, the

opening of the grab is controlled by a stationary abutment against whichthe extension of the movable jaw bears directly, i.e., under the bestcircumstances for security and precise operation.

The great simplicity of the device makes it easy to adjust, and theforce of applying the slide has no effect on the position of the opengrab.

Other features and advantages of the invention will become apparent fromthe following description, and from the annexed drawings, which show, asa nonlimiting example, an embodiment of a weft-transfer device for ashuttleless loom, especially of the type described and illustrated inFrench Pat. No. 1,290,867.

in the drawings,

FIG. 1 is a plan view, with certain parts removed, of a wefttransferdevice according to the present invention in the posi tion for drawing aweft thread;

FIG. 2 is a view corresponding to F I6. I showing the device towards theend of its exit passage; and

FIG. 3 is a view corresponding to FIG. 1 showing the device with theneedle near the end of its passage, where it is to catch a weft thread.

A weft-transfer device for a shuttleless weaving loom consists of aneedle indicated generally by l, and a system indicated generally by 2controlling the opening and closing of a grab.

The needle 1 reciprocates along reed 3 of the loom, and to this end, isfitted with a skid 4 adapted to run along the front face of said reed.The needle 1 is actuated by means of a balland-socket joint 5 at itsouter end through an appropriate system which does not form part of thepresent invention, and a detailed description of which can be found inthe abovementioned French Patent.

The needle 1 carries a grab indicated generally by 8 and consisting of afixed jaw 11 integral with the skid 4, and a movable jaw 12 pivotallymounted on the fixed jaw 11 by means of pivot pin 13.

The grab 8 is resiliently urged towards its closed position, i.e., forclamping a weft thread 10, by a compression spring 16 of which one endpresses against the inner face of a tail 17 on the movable jaw 12, andthe other end presses against a regulating screw 18 located in the skid4.

The grab 8 can be maintained in the open condition, as shown in FIG. 2,by retaining means consisting in this example of a slide 21 which has arecess 22 and which is mounted in a sliding fashion in the tubular body6 of the needle 1. The slide 21 is resiliently urged towards the tail 17of the jaw 12 of the grab by a compression spring 23 which is located inthe tubular body 6 of the needle 1, an of which one end presses againstthe face of the slide 21 opposite to the face with the recess 22, whileits other end presses against an internal collar 25 in the needle 1.

The slide 21 can release the tail 17 of the jaw 12 under the action ofneutralizing means which consist of a stop 28 belonging to the systemfor controlling opening and reengaging the grab and indicated by 2, thestop 28 being located in the path of an angled end portion 29 of a bolt27 which is slidable in a bore 31 in a collar 25, and in a bore 32 inanother similar collar 33, both being fixed in the tubular body of theneedle I, the other end of bolt 27 being fixed to the slide 21.

The stop 28 is fixed to a bracket 35 on the loom frame, at a point soplaced that, when the said stop 28 is struck by the angled end portion29 of the bolt 27, the grab is almost at the point at which it is tocatch a weft thread, which in this example is passed to it in the middleof the shed by a supply needle.

A diagrammatic illustration is given of a fine adjustment means forpositioning the stop 28, in the form of a rod 37 which is integral withsaid stop 28, and is fitted in a bore 38 in a boss 35, in which it canbe secured by a setscrew 39.

The means controlling the opening of the grab 8 consists of a camformation 42 formed by an enlargement projecting from the external faceof the tail 17 of the jaw 12, and by a roller 43 which forms part of thesystem indicated generally by 2, and which lies in the path of said cam42.

The roller 43 is mounted on one end of a lever 45 which can pivot on apin 46 carried by the support 35. A stop 47 limits the length of thepivotal movement of the lever 45 in the direction from the interior ofthe shed towards the outside, so that roller 43 obstructs the path ofthe cam 42 of the grab 8 when the needle 1 is moving to the left in thedrawing, but the pivoting movement of the lever 45 in the direction ofarrow f is free, so that the roller 43 can move clear of the cam 42 whenthe latter strikes it from left to right in the drawings, i.e., in theentry direction of the needle into the shed.

The parts of the jaws ll, 12 of the grab 8 adapted to catch and draw theweft thread 10, and indicated respectively by 51 and 52, are chromed orcovered for example, by a high-adhesion material, such as that known inthe trade by the name Vulcolan," or by ceramic plates, or by carbidewhen abrasive threads such as Verranne or natural silk threads, are tobe caught.

The weft-transfer device functions as follows.

It is first assumed that the necessary adjustments have already beenmade, i.e., the pressure of the clamping spring 16 for the jaws 11, 12of the grab 8 has been adjusted by means of the screw 18 according tothe characteristics of the threads to be caught, so that their tensiondoes not tend to open the pincer, and the stop 28 is suitably positionedto ensure closing of the grab 8 at exactly the right moment.

It is now assumed, for example, that needle 1 is carrying out its returnpassage into the shed as shown in FIG. 3, the grab 8 being held open bythe slide 21 urged by the spring 23. At the moment when the grab 8 isabout to catch the weft thread 10, the angled end portion 29 of the bolt27 strikes the fixed stop 28, and the adjustment is such that needle 1is not yet completely at its inner dead point, but must still travel adistance very slightly larger than the depth of the recess 22 in theslide 21, so that the needle 1, and thus the grab 8, continue theirmovement in the direction of the arrow f1, while the slide 21 isretained by the stop 28. The tail 17 of the jaw 12 is thus disengagedfrom said slide 21, and the spring 16 ensures rapid closure of the jaws1 1, 12 of the grab 8 on the weft thread 10.

The return run of the grab 8 takes place in the direction of the arrowf2 (FIG. 1), and the weft thread is carried from the middle of the shedtowards the corresponding edge. At the moment when the grab 8 is torelease the weft thread 10, its cam 42 strikes the roller 43 (FlG. 2),which cannot move, since the lever 45 carrying it is in contact with thestop 47. The cam 42, pushed in by the roller 43 against the action ofthe spring 16, therefore rapidly opens the grab 8, which thus releasesthe weft thread 10. This occurs in the vicinity of the external deadpoint of the needle 1. Simultaneously, as soon as the end of the tail 17of the jaw 12 is in front of the recess 22 of the slide 21, the latteris returned by the spring 23 so as to hold the grab 8, once again in theopen condition, as shown in FIG. 2. The needle 1 continues its outwardmovement a little longer, and the cam 42 moves past the roller 43.

When the needle 1 starts again in the reverse direction in order tocatch another weft thread in the middle of the shed, the cam 42 pushesback slightly the roller 43, pivoting the lever 45 in the direction ofarrow f1 (FIG. 2), without any modification in the condition of the grab8 resulting. This completes the cycle.

It will be noted that the stop 47, on the left-hand side of the lever45, retains the roller 42 in the position shown in the drawings, inwhich it depresses the cam 42 of the grab 8 at the end of the lattersexit passage; the weft thread is thus released exactly at the momentwhen the needle reaches its forward dead point, i.e., at the moment ofbeating-up of the weft.

However, if the stop 47 were placed on the other side of the lever 45,as shown at 47A, then the roller 43 would be moved clear at the momentwhen the cam 42 of the grab 8 moved towards the end of the latters exitpassage, so that said grab 8 would remain closed, not only until thevery end of its exit passage, but, again, until the moment when,returning in the opposite direction in order to enter the shed again,the cam 42 would meet the roller 43 whose lever 45 would contact thestop 47a, this time forcing the grab 8 to open and releasing the weftthread, but the latter would thus have been retained until after thecompletion of the beating-up of the weft, which may be desirable incertain cases, especially when the weft threads are elastomeric threads.Whatever the positioning of the stop 47 for limiting the pivotingmovement of the lever 45, the latter is resiliently returned against thestop 47 by means (not shown), for example, a spring.

A means of cleaning the grab 8 by a jet of air, for example, can beadvantageously provided, using the blower device described in our FrenchPat. No. 1,563,122, so that the grab 8 is always quite clean at themoment of catching a weft thread.

1 claim: 1. A weft-thread passing device for a shuttleless weaving loom,comprising a weft-thread pickup needle provided with a clamp having afixed jaw and a movable jaw urged by resilient return means towards thefixed jaw, means for retaining the movable jaw in an open condition,means for neutralizing the said retaining condition, means forneutralizing the said retaining means when the needle reaches a positionfor catching a weft thread, and means for controlling the opening of themovable jaw when the needle is near the end of its passage out of theshed, in which the movable jaw is pivotable on the fixed jaw about atransverse axis, and has an extension beyond said axis, the means forretaining the movable jaw in the open condition comprises a slidemovable longitudinally in the needle and resiliently urged against saidextension of the movable jaw, the means for controlling the opening ofthe movable jaw comprises a stationary abutment located in the path ofsaid extension of the movable jaw.

2. A device as in claim 1, in which said abutment is carried by asupport pivotable relative to a fixed stop member so as to engage thesame when said support is pivoted to a position in which said abutmentlies in said path of the jaw extension.

3. A device as in claim 2, in which said stop is arranged so as to limitthe movement of the support in the direction from the interior of theloom laterally towards the exterior.

4. A device as in claim 2, in which said stop is arranged so as to limitthe movement of the support in the direction from the exterior of theloom towards its interior.

5. A device as claimed in claim 1, in which said means for neutralizingsaid retaining means comprises a projection on a rod which is movablelongitudinally of the needle and is secured to said slide, and a stop inthe path of said projection.

6. A weft-thread passing device for a shuttleless weaving loomcomprising a weft-thread pickup needle provided with a clamp having afixed jaw and a movable jaw urged by resilient return means towards thefixed jaw, means for retaining the movable jaw in an open condition,means for neutralizing the said retaining means when the needle reachesa position for catching a weft thread, and means for controlling theopening of the movable jaw when the needle is near the end of itspassage out of the shed, in which the movable jaw is pivotable on thefixed jaw about a transverse axis, and has an extension beyond saidaxis, the means for retaining the movable jaw in the open conditioncomprises a slide movable longitudinally in the needle and resilientlyurged against said extension of the movable jaw, said means forneutralizing said retaining means comprises a projection on a bolt whichis movable longitudinally of the needle and is secured to said slide,and a stop in the path of said projection, the means for controlling theopening of the movable jaw comprises a stationary abutment located inthe path of said extension of the movable jaw.

7. A device as claimed in claim 6, in which said extension of themovable jaw has a cam-shaped enlargement for engaging said abutment.

8. A device as claimed in claim 6, in which said slide has a recess inwhich said extension of the movable jaw engaged in the open condition ofthe clamp.

1. A weft-thread passing device for a shuttleless weaving loom,comprising a weft-thread pickup needle provided with a clamp having afixed jaw and a movable jaw urged by resilient return means towards thefixed jaw, means for retaining the movable jaw in an open condition,means for neutralizing the said retaining condition, means forneutralizing the said retaining means when the needle reaches a positionfor catching a weft thread, and means for controlling the opening of themovable jaw when the needle is near the end of its passage out of theshed, in which the movable jaw is pivotable on the fixed jaw about atransverse axis, and has an extension beyond said axis, the means forretaining the movable jaw in the open condition comprises a slidemovable longitudinally in the needle and resiliently urged against saidextension of the movable jaw, the means for controlling the opening ofthe movable jaw comprises a stationary abutment located in the path ofsaid extension of the movable jaw.
 2. A device as in claim 1, in whichsaid abutment is carried by a support pivotable relative to a fixed stopmember so as to engage the same when said support is pivoted to aposition in which said abutment lies in said path of the jaw extension.3. A device as in claim 2, in which said stop is arranged so as to limitthe movement of the support in the direction from the interior of theloom laterally towards the exterior.
 4. A device as in claim 2, in whichsaid stop is arranged so as to limit the movement of the support in thedirection from the exterior of the loom towards its interior.
 5. Adevice as claimed in claim 1, in which said means for neutralizing saidretaining means comprises a projection on a rod which is movablelongitudinally of the needle and is secured to said slide, and a stop inthe path of said projection.
 6. A weft-thread passing device for ashuttleless weaving loom comprising a weft-thread pickup needle providedwith a clamp having a fixed jaw and a movable jaw urged by resilieNtreturn means towards the fixed jaw, means for retaining the movable jawin an open condition, means for neutralizing the said retaining meanswhen the needle reaches a position for catching a weft thread, and meansfor controlling the opening of the movable jaw when the needle is nearthe end of its passage out of the shed, in which the movable jaw ispivotable on the fixed jaw about a transverse axis, and has an extensionbeyond said axis, the means for retaining the movable jaw in the opencondition comprises a slide movable longitudinally in the needle andresiliently urged against said extension of the movable jaw, said meansfor neutralizing said retaining means comprises a projection on a boltwhich is movable longitudinally of the needle and is secured to saidslide, and a stop in the path of said projection, the means forcontrolling the opening of the movable jaw comprises a stationaryabutment located in the path of said extension of the movable jaw.
 7. Adevice as claimed in claim 6, in which said extension of the movable jawhas a cam-shaped enlargement for engaging said abutment.
 8. A device asclaimed in claim 6, in which said slide has a recess in which saidextension of the movable jaw engaged in the open condition of the clamp.